Graphene oxide/N-CuMe2Pc nanorod hybrid nanocomposite as efficient visible light photocatalyst for aqueous Cr(VI) reduction

In this study, a nanocomposite based on graphene oxide (GO) and non-peripheral octamethyl-substituted copper (II) phthalocyanine (N-CuMe2Pc) nanorod as photosensitizer, was synthesized and characterized by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-vis diffuse reflectance spectroscopy, FTIR and Raman spectroscopy. For the first time, the photocatalytic activity of GO/Pc nanocomposite was tested for the reduction of aqueous chromium (VI) (10 mg/L) as a model pollutant, and the results were compared with those of pure N-CuMe2Pc and GO. Visible light was used as source and Cr(VI) concentration was monitored during 120 min of treatment period. Up to 95% photocatalytic reduction of toxic Cr(VI) ions confirms that GO/Pc nanocomposite photocatalyst is clearly effective for wastewater treatment. Meanwhile, neat GO and N-CuMe2Pc nanorod were able to reduce only less than 10% of initial Cr(VI) ions. The reusability of the developed photocatalyst was also investigated. The retained amount of Cr(VI) increased from 2% at first cycle to around 17% at third cycle, due to loss of photocatalyst during collection process and morphology changes from nanorods to nanoparticles. Our results demonstrate the remarkably improved photocatalytic performance of GO/Pc nanocomposite for the practical application in wastewater remediation.